Retraction Mechanism for Medical Device

ABSTRACT

A device comprises a retractable shaft; a shaft biasing spring; and an actuator button. The retractable shaft is biased away from the actuator button by the shaft biasing spring. A magnetic attracting force is created between the retractable shaft and the actuator button upon actuation of the actuator button. Before actuation, a distance between the actuator button and the retractable shaft is great enough that the magnetic attracting force is less than a biasing force of the shaft biasing spring such that the retractable shaft is biased away from the actuator button. Upon actuation, the actuator button is depressed to make the distance between the actuator button and the retractable shaft sufficiently small such that the magnetic attracting force is greater than the biasing force of the shaft biasing spring to allow the retractable shaft to be biased towards the actuator button.

CROSS REFERENCE

This patent application is a continuation of patent application U.S.Ser. No. 15/464,434, filed on Mar. 21, 2017, which claims priority toProvisional Patent Application U.S. 62/310,911, filed on Mar. 21, 2016,the disclosures of which are incorporated by reference herein in theirentireties.

BACKGROUND Field of the Invention

The exemplary and non-limiting embodiments described herein relate todevices having retraction mechanisms and, more specifically, to deviceshaving retraction mechanisms based on the use of magnetics.

BRIEF DESCRIPTION OF PRIOR DEVELOPMENTS

U.S. Pat. No. 8,100,891 describes a medical appliance having a firstsetting device disposed at an outer side on a housing of the applianceand a second setting device disposed in the interior of the appliance,the first and second setting devices each comprising magnet elementsthat cooperate in such a way that one setting device actuates the othersetting device for the transmission of adjustments. European Patent No.EP2291130 describes a cutting tool that includes an outer tubular memberhaving a first magnet and an inner tubular member having a secondmagnet, the inner tubular member being slidably disposed within theouter tubular member such that an attractive force between the firstmagnet and the second magnet creates a preload force between the innertubular member and the outer tubular member.

SUMMARY

In accordance with one aspect of the invention, a device comprises aretractable shaft; a shaft biasing spring; and an actuator button. Theretractable shaft is biased away from the actuator button by the shaftbiasing spring. A magnetic attracting force is created between theretractable shaft and the actuator button upon actuation of the actuatorbutton. Before actuation, a distance between the actuator button and theretractable shaft is great enough that the magnetic attracting force isless than a biasing force of the shaft biasing spring such that theretractable shaft is biased away from the actuator button. Uponactuation, the actuator button is depressed to make the distance betweenthe actuator button and the retractable shaft sufficiently small suchthat the magnetic attracting force is greater than the biasing force ofthe shaft biasing spring to allow the retractable shaft to be biasedtowards the actuator button.

In accordance with another aspect of the invention, a device comprises aretractable shaft and an actuator button. A first end of the retractableshaft includes a first magnet having a polarity and a first end of theactuator button includes a second magnet having the same polarity as thefirst magnet such that the first end of the retractable shaft isrepelled from the first end of the actuator button. When the actuatorbutton is pressed the first end of the actuator button travels past thefirst end of the retractable shaft such that the first magnet and thesecond magnet drive the retractable shaft towards the actuator button.

In accordance with another aspect of the invention, a method comprisesproviding a housing; providing a shaft having a medical tool locatedthereon, the shaft being slidably positioned in the housing and biasedto extend from a distal end of the housing; providing an actuator buttonslidably positioned in the housing, the actuator button extending from aproximal end of the housing; and providing a magnetic attracting forcebetween the shaft and the actuator button upon actuation of the actuatorbutton. Before actuation, a distance between the actuator button and theshaft is great enough that the magnetic attracting force is less than abiasing force acting on the shaft such that the shaft is biased awayfrom the actuator button. Upon actuation, the actuator button isdepressed to make the distance between the actuator button and the shaftsufficiently small such that the magnetic attracting force is greaterthan the biasing force acting on the shaft to allow the shaft to bebiased towards the actuator button.

In accordance with another aspect of the invention, a method comprisesmaneuvering a medical device to contact a tissue surface of a patient,the medical device having a shaft biased to extend from a distal end ofa housing and further having an actuator button disposed at a proximalend of the housing, the shaft further having a medical tool associatedtherewith for contacting the tissue surface of the patient; andactuating the actuator button to retract the shaft into the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and other features of the invention are explainedin the following description, taken in connection with the accompanyingdrawings, wherein:

FIG. 1A is a section view of one exemplary embodiment of a device havinga tool retraction mechanism using opposing polarities of two magnets;

FIG. 1B is a section view of the device of FIG. 1A illustrating oneexemplary operation of the device;

FIG. 2 is a section view of another exemplary embodiment of a devicehaving a tool retraction mechanism using a magnet and a ferromagneticmaterial;

FIG. 3A is a section view of another exemplary embodiment of a devicehaving a tool retraction mechanism using similar polarities of twomagnets;

FIGS. 3B-3D are section views of the device of FIG. 3A illustrating anoperation of the device; and

FIG. 4 is a side view with inset of another exemplary embodiment of adevice having a tool retraction mechanism, the device being usable in asurgical procedure.

DETAILED DESCRIPTION

Referring to FIG. 1A, one exemplary embodiment of a device is designatedgenerally by the reference number 100 and is hereinafter referred to as“device 100.” Although the features will be described with reference tothe example embodiments shown in the drawings, it should be understoodthat features can be embodied in many alternate forms. In addition, anysuitable size, shape, or type of elements or materials may be used.

Device 100 comprises a gripping portion or handle 105 having a proximalend 110 and a distal end 115. A tool 120 is slidably positioned in thehandle 105 so as to extend from the distal end 115. An actuator in theform of a button mechanism 130 is slidably positioned in the handle 105so as to extend from the proximal end 110. The tool 120 may beretractable into the handle 105 upon actuation of the button mechanism130. The device 100 is not limited to the actuator being the buttonmechanism 130, however, as the actuator may be a sliding mechanismprotruding from a side of the handle 105.

The tool 120 may comprise a shaft 135, which may be slidable in thedistal end 115 partially through a front opening in the handle 105 andpartially through a forward shoulder 140. The tool 120 may furthercomprise a shaft collar 145 or O-ring located on a portion of the shaft135 within the handle 105 to retain the tool 120 in the front opening atthe distal end 115 of the handle 105. The tool 120 may further comprisea biasing spring 150 (e.g., a coil spring) positioned around the shaft135 and aft of the shaft collar 145 and forward of the forward shoulder140. The biasing spring 150 may bias the tool 120 in the distaldirection through the front opening and may hold the tool 120 in astationary position relative to the handle 105. The shaft 135 maysubstantially be a rod or a tube and may form all or a portion of a toolfor a medical device, such as a needle, a knife, a blade, a cannula, atrocar, or the like.

The button mechanism 130 may be slidable in the proximal end 110 of thehandle 105 partially through a rear opening and partially through a rearshoulder 155. The button mechanism 130 may comprise a control surface160 and a plunger 165, which may be integral with or attached to thecontrol surface 160. The button mechanism 130 may further comprise abutton collar 170 or O-ring located on a portion of the plunger 165within the handle 105 to retain the plunger 165 in the rear opening atthe proximal end 110 of the handle 105. The button mechanism 130 mayfurther comprise a button return spring 175 (e.g., a coil spring)positioned around the plunger 165 and aft of the rear shoulder 155 andforward of the button collar 170. The button return spring 175 may biasthe plunger 165 in the proximal direction through the rear opening andmay hold the control surface 160 in a stationary position relative tothe handle 105.

The biasing spring 150 and the button return spring 175 may each biasthe tool 120 and the button mechanism 130, respectively, in opposingdirections.

A proximal end of the shaft 135 may include or be configured as a shaftmagnet 180, and a distal end of the plunger 165 may include or beconfigured as a button magnet 185. The shaft magnet 180 and the buttonmagnet 185 define a magnetic mechanism that creates an attractive forcebetween the proximal end of the shaft 135 and the distal end of theplunger 165. To create the attractive force, the shaft magnet 180 andthe button magnet 185 may be arranged as magnetic poles having oppositepolarities (e.g., one magnet is a north pole, and the other magnet is asouth pole).

Referring to FIG. 1B, the operation of device 100 is shown. When thecontrol surface 160 of the button mechanism 130 is actuated by pushingin the forward direction (the “button” is pressed), the button returnspring 175 may be compressed and the distal end of the plunger 165 movedinto close proximity with the proximal end of the shaft 135. Because theshaft magnet 180 and the button magnet 185 are of opposing polarities,the shaft magnet 180 and the button magnet 185 attract each other. Thebiasing spring 150 is configured to have a force that may be overcome bythe attraction of the shaft magnet 180 and the button magnet 185. Inovercoming the force of the biasing spring 150, the shaft 135 is causedto move in the proximal direction and retract the distal end of the tool120. The lengths of the shaft 135 and the plunger 165 and theirpositioning in the handle 105 are configured to, in conjunction withsuitable actuation of the button mechanism 130, retract the tool 120 adesired distance 190 relative to a pre-retracted position 195. In oneexemplary embodiment, when the button mechanism 130 is actuated, theshaft magnet 180 may be attracted to the button magnet 180 as long asthe “button” is depressed. When the “button” is released, the biasingforces of the biasing spring 150 and the button return spring 175 mayovercome the magnetic attraction, and the biasing spring 150 and thebutton return spring 175 extend. In another exemplary embodiment, thebutton mechanism 130 may be a one-time use mechanism that retracts theshaft 135 to the proximal position, the magnetic attraction beinggreater than the biasing force of either of the biasing spring 150 andthe button return spring 175. In such a configuration, the shaft 135 andthe plunger 165 may remain in the attracted configuration.

Referring now to FIG. 2, another exemplary embodiment of a device isdesignated generally by the reference number 200 and is hereinafterreferred to as “device 200.” Device 200 may be similar in some exemplaryaspects to device 100 and may have a handle 205, a tool 220 with a shaft235, and a button mechanism 230 with a plunger 265 and a button returnspring 275, but in device 200 one of a rearward portion of the shaft 235and a forward portion of the plunger 265 includes a magnet 280, and theother of the rearward portion of the shaft 235 and the forward portionof the plunger 265 includes a ferromagnetic material 285. As shown, theshaft 235 includes the magnet 280 and the plunger 265 includes theferromagnetic material 285. However, the device 200 is not limited inthis regard, and the shaft 235 may include the ferromagnetic material285 and the plunger 265 may include the magnet 280. When a controlsurface 260 is actuated by pushing in the forward direction (the“button” is pressed), the plunger 265 is moved in the distal direction,and the magnet 280 is attracted to the ferromagnetic material 285,thereby drawing the shaft 235 in the proximal direction for retraction.

In either the configuration of the device 100 of FIG. 1A or theconfiguration of the device 200 of FIG. 2, in an initial state (beforepressing the button), the distance between the proximal end of the shaft135, 235 and the distal end of the plunger 165, 265 is sufficientlygreat such that a magnetic attraction force may be overcome by thebiasing forces of the biasing spring 150, 250 and the button returnspring 175, 275, so that the button mechanism 130, 230 is biasedproximally relative to the handle 105, 205 and the shaft 135, 235 isbiased distally relative to the handle 105, 205.

In either of the foregoing exemplary embodiments, either the biasingspring 150, 250 or the button return spring 175, 275 is optional.

Also, in either of the foregoing exemplary embodiments when the biasingspring 150, 250 and/or the button return spring 175, 275 are used, thecontrol surface 160, 260 may be released and the button return spring175, 275 may drive the button mechanism 130, 230 in the proximaldirection. In doing so, the tool 120, 220 may be further retracted. Inanother exemplary embodiment, if the biasing spring 150 is stronger thanthe button return spring 175 but the magnetic attraction between the twois not overcome by the springs, then the shaft 135 and the button magnet185 may remain locked together magnetically, and both would be driven toa more distal position. Doing so would render the button mechanism 130to a more distal position, which may be practical for a one-time usedevice.

Referring now to FIG. 3A, a device 300 comprises a gripping portion orhandle 305 having a proximal end 310 and a distal end 315. A tool 320,which may be similar in some exemplary aspects to the tool of device100, is slidably positioned in the handle 305 so as to extend from thedistal end 315. An actuator in the form of a button mechanism 330 isslidably positioned in the handle 305 so as to extend from the proximalend 310. The tool 320 may be retractable into the handle 305 uponactuation of the button mechanism 330.

The tool 320 may comprise a shaft 335, which may be slidable in thedistal end 315 of the handle 305 partially through a front opening. Thetool 320 may further comprise a shaft collar 345 or O-ring located on aportion of the shaft 335 within the handle 305 to retain the tool 320 inthe distal end 315 of the handle 305. Optionally, a biasing spring(e.g., a coil spring) may be positioned around the shaft 335 and aft ofthe shaft collar 345 and forward of a forward shoulder. Such a biasingspring, if present, may bias the tool 320 in the distal directionthrough the front opening, similar to the shaft 135 of the tool 120 ofthe device 100. With regard to the tool 320, the shaft 335 maysubstantially be a rod or a tube and may form all or a portion of a toolfor a medical device, such as a needle, a knife, a blade, a cannula, atrocar, or the like.

The button mechanism 330 may be slidable in the proximal end 310 of thehandle 305 partially through a rear opening and partially through a rearshoulder 355. The button mechanism 330 may comprise a control surface360 and a plunger 365, which may be attached to or integral with thecontrol surface 360. The button mechanism 330 may further comprise abutton collar 370 or O-ring located on a portion of the plunger 365within the handle 305 to retain the plunger 365 in the proximal end 310of the handle 305. A cavity 388 may be formed in a forward end of theplunger 365 for receiving the shaft 335 during operation of the device300. Optionally, the button mechanism 330 may further comprise a buttonreturn spring 375 (e.g., a coil spring) positioned around the plunger365 and aft of the rear shoulder 355 and forward of the button collar370. Such a button return spring 375, if present, may bias the plunger365 in the proximal direction through the rear opening and hold thecontrol surface 360 in a stationary position relative to the handle 305.

The shaft 335 may be configured as a shaft magnet 380 (or it may includethe shaft magnet 380 at a proximal end of the shaft 335) such that aproximal end of the shaft 335 has a magnetic polarity. The plunger 365may also be configured as a plunger magnet 385 (or it may include theplunger magnet 385 at a distal end of the plunger 365) such that adistal end of the plunger 365 proximate a mouth of the cavity 388 hasthe same polarity as the proximal end of the shaft 335. A bottom of thecavity 388 or an area proximate the bottom of the cavity 388, however,has the opposite polarity as at the mouth of the cavity 388. The shaftmagnet 380 and the plunger magnet 385 define a magnetic mechanism ormagnetic means that creates a repulsive force between the proximal endof the shaft 335 and the distal end of the plunger 365. The repulsiveforce is created by the shaft magnet 380 and the plunger magnet 385arranged as magnetic poles having the same polarities (both magnets arenorth poles or both magnets are south poles). As shown, both the shaftmagnet 380 and the plunger magnet 385 are north poles, with a moredistal portion of the shaft 335 being a south pole and a more proximalportion of the plunger 365 also being a south pole. The present device300 is not so limited, however, as both of these polarities may bereversed. In any configuration, in an initial state, the shaft magnet380 and the plunger magnet 385 repel each other and are driven away fromeach other, without need of a biasing spring.

Referring now to FIG. 3B, the plunger magnet 385 at the distal end ofthe plunger 365 has the cavity 388 in which the proximal end of theshaft magnet 380 may be received. Thus, as the control surface 360 isactuated by pushing in the forward direction (the “button” is pressed),the plunger magnet 385 at the mouth of the cavity 388 may move over theshaft magnet 380 on the proximal end of the shaft 335. As the plungermagnet 385 and the shaft magnet 380 pass each other as indicated byarrow 392, the repulsive force drives the shaft 335 (and the tool 320)in the proximal direction, thereby retracting the tool 320. In oneexemplary embodiment, the distal end of the plunger 365 may beconfigured simply as a cylinder of non-ferromagnetic material having thecavity for receiving the shaft 335, with the plunger magnet 385configured as a donut-shaped member over the distal end of the plunger365. In another exemplary embodiment, the shaft magnet 380 and theplunger magnet 385 may be coaxially arranged.

Referring now to FIG. 3C, upon additional pressing of the controlsurface 360, the “button” is pressed farther into the handle 305, andthe plunger magnet 385 is moved farther past the shaft magnet 380. Indoing so, the repulsive force between the shaft magnet 380 on theproximal end of the shaft 335 and the plunger magnet 385 on the distalend of the plunger 365 becomes weaker, but an attractive force 394 maybe generated between the plunger magnet 385 on the distal end of theplunger 365 and the more distal portion of the shaft 335. Thisattractive force 394 may cause the retraction of the tool 320

Referring now to FIG. 3D, in an embodiment in which the optional buttonreturn spring 375 is incorporated into the button mechanism 330,releasing the control surface 360 may return the button mechanism 330 toa pre-pressed state, thereby retracting the tool 320 completely (orsubstantially completely) into the handle 305.

Any of the mechanisms of the above-described embodiments may beapplicable to devices such as trocars, needles, blades, and the like.

Referring now to FIG. 4, another exemplary embodiment of a device isdesignated generally by the reference number 400 and is hereinafterreferred to as “device 400.” Device 400 is a medical device andcomprises a handle 405 having a proximal end 410 and a distal end 415,with a tool 420 located in the distal end 415. A button mechanism 430 islocated in the proximal end 410 and is operably coupled to the tool 420using a magnetic mechanism as in the exemplary embodiments describedherein so as to cause the retraction of the tool 420 when the buttonmechanism 430 is actuated. The tool 420 may comprise a sharpened cannulaor knife 417 around which a removable vent tube 419 is positioned.

In one exemplary operation of the device 400, a user may maneuver thedevice 400 so as to insert the knife 417 through an epidermis or otherlayer of tissue 421 of a patient to make an opening. As the knife 417 isinserted farther, an outer surface of the vent tube 419 (which may beangled as shown) spreads the epidermis or tissue to define the openingof a desired size. Once the vent tube 419 is in place in the opening,the button mechanism 430 is actuated, and the knife 417 is retractedfrom the opening and the vent tube 419. The device 400 may then beseparated from the vent tube 419, leaving the vent tube 419 in theopening in the patient.

In one example, a device comprises a retractable shaft; a shaft biasingspring; and an actuator button. The retractable shaft is biased awayfrom the actuator button by the shaft biasing spring. A magneticattracting force is created between the retractable shaft and theactuator button upon actuation of the actuator button. Before actuation,a distance between the actuator button and the retractable shaft isgreat enough that the magnetic attracting force is less than a biasingforce of the shaft biasing spring such that the retractable shaft isbiased away from the actuator button. Upon actuation, the actuatorbutton is depressed to make the distance between the actuator button andthe retractable shaft sufficiently small such that the magneticattracting force is greater than the biasing force of the shaft biasingspring to allow the retractable shaft to be biased towards the actuatorbutton.

The actuator button may comprise a button return spring that biases theactuator button away from the retractable shaft. The device may furthercomprise a first magnet on the retractable shaft and a second magnet onthe actuator button, the first magnet and the second magnet being ofopposite polarities to create the magnetic attracting force. The devicemay further comprise a first magnet on one of the retractable shaft andthe actuator button and a ferromagnetic material on the other of theretractable shaft and the actuator button. The device may furthercomprise a housing in which the retractable shaft and the actuatorbutton are slidably arranged. The retractable shaft may comprise acollar positioned thereon, and the housing may comprise a shoulderpositioned therein, and the shaft biasing spring may be compressiblypositioned between the collar and the shoulder. The retractable shaftmay include a medical tool.

In another example, a device comprises a retractable shaft and anactuator button. A first end of the retractable shaft includes a firstmagnet having a polarity and a first end of the actuator button includesa second magnet having the same polarity as the first magnet such thatthe first end of the retractable shaft is repelled from the first end ofthe actuator button. When the actuator button is pressed the first endof the actuator button travels past the first end of the retractableshaft such that the first magnet and the second magnet drive theretractable shaft towards the actuator button.

The device may further comprise a housing in which the retractable shaftand the actuator button are slidably arranged. The actuator button maycomprise a button return spring positioned in the housing, the buttonreturn spring being configured to bias the actuator button away from theretractable shaft. The first end of the actuator button may comprise aplunger on which the second magnet is one of coupled to or integral withthe plunger having a cavity for receiving the first magnet. Uponreceiving the first magnet in a mouth portion of the cavity, theretractable shaft may be repelled farther into the cavity. Upon theretractable shaft being repelled farther into the cavity, an attractiveforce between the second magnet and a distal portion of the retractableshaft may draw the distal portion of the retractable shaft to the secondmagnet. Upon the retractable shaft being repelled farther into thecavity, an attractive force between the first magnet and a bottom of thecavity may draw the first magnet to the bottom of the cavity. Theretractable shaft may include a medical tool.

In another example, a method comprises providing a housing; providing ashaft having a medical tool located thereon, the shaft being slidablypositioned in the housing and biased to extend from a distal end of thehousing; providing an actuator button slidably positioned in thehousing, the actuator button extending from a proximal end of thehousing; and providing a magnetic attracting force between the shaft andthe actuator button upon actuation of the actuator button. Beforeactuation, a distance between the actuator button and the shaft is greatenough that the magnetic attracting force is less than a biasing forceacting on the shaft such that the shaft is biased away from the actuatorbutton. Upon actuation, the actuator button is depressed to make thedistance between the actuator button and the shaft sufficiently smallsuch that the magnetic attracting force is greater than the biasingforce acting on the shaft to allow the shaft to be biased towards theactuator button.

The method may further comprise providing a button return springcooperably associated with the actuator button to bias the actuatorbutton away from the shaft. The method may further comprise providing afirst magnet on the shaft and a second magnet on the actuator button,the first magnet and the second magnet being of opposite polarities tocreate the magnetic attracting force.

In another example, a method comprises maneuvering a medical device tocontact a tissue surface of a patient, the medical device having a shaftbiased to extend from a distal end of a housing and further having anactuator button disposed at a proximal end of the housing, the shaftfurther having a medical tool associated therewith for contacting thetissue surface of the patient; and actuating the actuator button toretract the shaft into the housing.

In another example, a medical device comprises a housing having a distalend and a proximal end; a retractable shaft slidably located in thehousing so as to extend from the distal end; and an actuatormagnetically couplable to the retractable shaft and slidably located inthe housing so as to extend from the proximal end. Upon actuation, theactuator is depressed to allow the retractable shaft to be magneticallybiased towards the actuator and retracted into the housing.

It should be understood that the foregoing description is onlyillustrative. Various alternatives and modifications can be devised bythose skilled in the art. For example, features recited in the variousdependent claims could be combined with each other in any suitablecombination(s). In addition, features from different embodimentsdescribed above could be selectively combined into a new embodiment.Accordingly, the description is intended to embrace all suchalternatives, modifications, and variances which fall within the scopeof the appended claims.

We claim:
 1. A device, comprising: a retractable shaft; a shaft biasingspring; and an actuator button; wherein the retractable shaft is biasedaway from the actuator button by the shaft biasing spring; wherein amagnetic attracting force is created between the retractable shaft andthe actuator button upon actuation of the actuator button; whereinbefore actuation, a distance between the actuator button and theretractable shaft is great enough that the magnetic attracting force isless than a biasing force of the shaft biasing spring such that theretractable shaft is biased away from the actuator button; and whereinupon actuation, the actuator button is depressed to make the distancebetween the actuator button and the retractable shaft sufficiently smallsuch that the magnetic attracting force is greater than the biasingforce of the shaft biasing spring to allow the retractable shaft to bebiased towards the actuator button.
 2. The device of claim 1, whereinthe actuator button comprises a button return spring that biases theactuator button away from the retractable shaft.
 3. The device of claim1, further comprising a first magnet on the retractable shaft and asecond magnet on the actuator button, the first magnet and the secondmagnet being of opposite polarities to create the magnetic attractingforce.
 4. The device of claim 1, further comprising a first magnet onone of the retractable shaft and the actuator button and a ferromagneticmaterial on the other of the retractable shaft and the actuator button.5. The device of claim 1, further comprising a housing in which theretractable shaft and the actuator button are slidably arranged.
 6. Thedevice of claim 5, wherein the retractable shaft comprises a collarpositioned thereon, and wherein the housing comprises a shoulderpositioned therein, and wherein the shaft biasing spring is compressiblypositioned between the collar and the shoulder.
 7. The device of claim1, wherein the retractable shaft includes a medical tool.
 8. A device,comprising: a retractable shaft; a shaft biasing spring; and an actuatorbutton; further comprising a housing in which the retractable shaft andthe actuator button are slidably arranged; wherein the retractable shaftis biased away from the actuator button by the shaft biasing spring;wherein a magnetic attracting force is created between the retractableshaft and the actuator button upon actuation of the actuator button;wherein before actuation, a distance between the actuator button and theretractable shaft is great enough that the magnetic attracting force isless than a biasing force of the shaft biasing spring such that theretractable shaft is biased away from the actuator button; and whereinupon actuation, the actuator button is depressed to make the distancebetween the actuator button and the retractable shaft sufficiently smallsuch that the magnetic attracting force is greater than the biasingforce of the shaft biasing spring to allow the retractable shaft to bebiased towards the actuator button.
 9. The device of claim 8, whereinthe actuator button comprises a button return spring that biases theactuator button away from the retractable shaft.
 10. The device of claim8, further comprising a first magnet on the retractable shaft and asecond magnet on the actuator button, the first magnet and the secondmagnet being of opposite polarities to create the magnetic attractingforce.
 11. The device of claim 8, further comprising a first magnet onone of the retractable shaft and the actuator button and a ferromagneticmaterial on the other of the retractable shaft and the actuator button.12. The device of claim 8, wherein the retractable shaft comprises acollar positioned thereon, and wherein the housing comprises a shoulderpositioned therein, and wherein the shaft biasing spring is compressiblypositioned between the collar and the shoulder.
 13. The device of claim8, wherein the retractable shaft includes a medical tool.
 14. A device,comprising: a retractable shaft; and an actuator button; wherein a firstend of the retractable shaft includes a first magnet having a polarityand a first end of the actuator button includes a second magnet havingthe same polarity as the first magnet such that the first end of theretractable shaft is repelled from the first end of the actuator button;wherein when the actuator button is pressed the first end of theactuator button travels past the first end of the retractable shaft suchthat the first magnet and the second magnet drive the retractable shafttowards the actuator button; and wherein the first end of the actuatorbutton comprises a plunger on which the second magnet is one of coupledto or integral with the plunger having a cavity for receiving the firstmagnet.
 15. The device of claim 14, further comprising a housing inwhich the retractable shaft and the actuator button are slidablyarranged.
 16. The device of claim 15, wherein the actuator buttoncomprises a button return spring positioned in the housing, the buttonreturn spring being configured to bias the actuator button away from theretractable shaft.
 17. The device of claim 14, wherein upon receivingthe first magnet in a mouth portion of the cavity, the retractable shaftis repelled farther into the cavity.
 18. The device of claim 17, whereinupon the retractable shaft being repelled farther into the cavity, anattractive force between the second magnet and a distal portion of theretractable shaft draws the distal portion of the retractable shaft tothe second magnet.
 19. The device of claim 17, wherein upon theretractable shaft being repelled farther into the cavity, an attractiveforce between the first magnet and a bottom of the cavity draws thefirst magnet to the bottom of the cavity.
 20. The device of claim 14,wherein the retractable shaft includes a medical tool.